Glucosylceramide synthase inhibitors have been shown to reduce the levels of glucosylceramide and glucosylsphingosine in the central nervous system, decelerate the accumulation of α-syn, ubiquitin and tau proteins and improve cognitive and behavioral outcome in a GBA-associated PD mouse model (Sardi et al. 2017). The gene discussed is MAPT; the disease is Parkinson disease.